TABLE OF CONTENTS When one buys gasoline for the car, one expects to get exactly one gallon of gas when paying for one gallon. When one takes a child's temperature, one needs to be assured that the reading is correct. When the remote level indicator on a tank indicates that it is 90% full, can one be sure that the tank is not running over? Can the manufacturer be sure the process control system is providing the proper mix for the product? When a combustible mixture is being heated to just under the flash point, can one be sure that it won't ignite?
| Note | Continuing calibration assures the equipment continually meets the specifications required at installation, and it should be checked regularly thereafter. Calibration after any maintenance ensures the equipment still conforms to the required calibration data. Customers require letters of conformance or certificates of calibration. |
Calibration is a test during which known measurement values are applied to a device and a corresponding instrument reading is compared to a standard series of values the device was to measure, receive, or transmit. These known measurement values are usually obtained by using test equipment that has traceability to the National Institute of Standards and Technology (NIST), formerly the National Bureau of Standards (NBS). Data so obtained are used to determine the locations at which scale graduations are to be placed, to adjust the output to bring it to the desired value within a specified tolerance, and to ascertain the...
